A clinical examination with collection of demographic data (gender, age, weight, size) will be noted. All co-morbidities as well as situations of potential risk of infection (diabetes type 2 steroids ongoing chronic renal failure, body mass index above 30, age over 65 years, recent surgery, serum albumin less than 35 , chronic obstructive bronchitis, tobacco weaned or unweaned? coronary insufficiency) will be noted (CRF).